Agence science-Presse (www.sciencepresse.qc.ca)
SCIENCE. At the height of COVID, the scientific community benefited from budgets to initiate research at unprecedented speed. Vaccines have saved tens of millions of lives and, at the same time, the accumulated knowledge of symptoms has served thousands of hospitals. The question then was to fight a new virus. But today the question has become: how to fight a virus that has become too familiar?
When they arrived on the scene, some of the vaccines — among the dozen approved in a large number of countries — had a 95% effectiveness rate in reducing serious cases leading to hospitalizations. Two years later, the variants have of course eroded this effectiveness, just as they have eroded that of drugs that had raised a lot of hope, such as monoclonal antibodies.
They remain effective at different levels from then, but the problem no longer arises in the same way. At the start of the vaccination campaign, these vaccines had been tested, ironically pathologist Benjamin Mazer in The Atlantic, “on a type of human being that practically no longer exists: Homo uninoculatus uninfectus, that is to say a person who has neither been sick with COVID nor been vaccinated”.
The original vaccines, like drugs like Paxlovid, even excluded from their initial studies patients who had already had COVID, so that they could compare groups who had a “clean record” of this virus. A situation which would obviously be impossible to reproduce today: almost everyone has been exposed to it, by at least one infection and by at least one dose of the vaccine. In 2023, measuring the exact effectiveness of one treatment — not just a vaccine — versus another has therefore become a puzzle.
And as if it were not already complex enough, another problem is added: there are fewer studies than at the height of the crisis. Data on efficacy against BA.5 variants are still circulating among researchers, while it is XBB.1.5 that has already become dominant in the United States.
Paradoxically, experts see this uncertainty as good and bad news. The good news is that even if we can no longer put a number on our risk, we can at least be sure that most of us are less at risk of severe consequences from COVID than we are. ‘three years ago. The bad news is that this finding does not include the millions of immunosuppressed people or the elderly with pre-existing conditions.
And the other bad news, infectious disease expert Paul Sax said in December, is that because of this uncertainty, we’re unable to make predictions about how variants will evolve in the future, or what the next wave will be. , or on its seriousness, for lack of reliable data.
Link to the original article https://www.sciencepresse.qc.ca/actualite/2023/01/11/covid-combattre-virus-devenu-familier